The isotope of silicon having an atomic weight of 32 (Si-32) is useful, e.g., as a tracer for silicon, for dating of geological and cosmological processes and as a potential generator of the daughter nuclide phosphorus-32. Silicon-32 has previously been produced by: (1) spallation of vanadium with high energy protons, followed by extraction as molybdosilicic acid and purification by anion exchange; and (2) reaction of a sulfur target with protons from a synchrocyclotron, followed by recovery by distillation as H.sub.2 SiF.sub.6 from a concentrated sulphuric acid solution. Each of the former processes used materials such as n-butanol or hydrofluoric acid that are undesirable to use either due to safety or to mixed waste disposal problems. Further, neither of the previous processes have been able to produce a high specific activity silicon-32 product.
Accordingly, it is an object of this invention to provide a silicon-32 product characterized as having a high specific activity, i.e., greater than about 300 Becquerels per microgram of silicon.
It is a further object of this invention to provide a process for production of silicon-32, preferably silicon-32 having a high specific activity.